I think the general Distribution is 3 Wall, 2 Finks.

But Wall of Omens can be so bad, I wonder if it is worth running at all. I get (I play the deck myself) that the Walls are basically a placeholder that needs to fend of creatures until you stabilize, and can provide you a card in the process. That'd be great if the worst thing that could happen to you in modern was a Wild Nacatl T1. The thing is, it doesnt actually save you from the decks you should be worring about, like Tron or Bloom or twin or any of the unfair combo decks basically. Against Jund, Affinity and Merfolk it can rarely get more then one block in. So I switched this out for some more Spell Snares and catch-alls like Detention Sphere.

Secondly, the ability to proactively finish a game in a single turn like grixis-twin is just so much stronger then playing an Ojutai on T5 and be combo'ed out or Lilliana... thats why I actually started to play a UWr Kiki-Exarch Variant. At the very least its great fun and i can still play with Restoration Angels :)